1. Field of This Invention
This invention relates to airborne vehicle referenced recording devices.
2. Prior Art
In airborne systems there is a need to record information displayed to the pilot, which is to be used for training, pilot performance evaluation, accident investigation or other purposes. In vehicles equipped with a so called Head-Up Display, information regarding attitude, course, etc., is presented to the pilot by means of a combining element, which allows such information to be superimposed on the outside world, with the pilot seeing such through the combiner. In order to record the composite data and outside world view as seen by the pilot, it has been necessary to employ a camera located between the pilot and the combiner.
This method has considerable disadvantages because the camera can not simultaneously expose the outside world and the total display seen by the pilot with sufficient resolution and accuracy. Furthermore, the optical part of the camera interfers with the pilot's outside view, which in some cases requires special procedures from his side during the flight mission. Due to these disadvantages the camera is attached only in missions where recording is urgent enough that the disturbance, caused by the application of the camera, can be accepted.